Sheet and method of producing same for the economical production of blanks



SHEET AND METHOD OF PRODUCING SAME FOR THE ECONOMICAL PRODUCTION OF BLANKS Filed April 3, -1942 FIG. I.

nu: FURM EHI-:ET

26 l INVENTOR.

Rnher WMEE 5B1-1g er' ATTORNEYS.

Patented Nov. 30, 1943 SHEET AND METHOD F PBODUCING SAME FOB TlE ECONOMICAL PRODUCTION 0F nobel-t w. Museum, Salisbury, Ma. Application april s; ma, semi No. 431.590

Clalms.

The present invention relates broadly to the art of cutting and punching sheets. It ls particularly well adapted, altho not necessarily liml ited, to the manufacture of can ends.

Heretofore it has been the practice to cut a number of disc-like elements of the same size from a rectangular sheet of material `in such manner that there is a considerable amount oi' waste material, and attempts have been made to utilize this waste material in the manufacture of secondary smaller disc-like elements or other fittings from the so-called recovery piece. However, it is questionable that there is much, if any, economy in doing this because of the time and labor necessary to punch these smaller disc-like elements or fittings from the recovery piece, or to segregate them from the main products of the sheet if both the main and secondary products are cut simultaneously. Furthermore, the quantity of secondary products that may be produced from a sheet of a given size is to a degree iixed, say for example, tour secondary products to twenty-eight main products. The demand for the number of secondary products may be greater than is supplied by this procedure, whereupon additional quantities must be produced by some other method, to supply the demand. On the other hand, the demand for the secondary products may be small, whereupon only a portion of those produced by the method are utilized, and many are wasted.

Even when sheet material is plentiful, the scrap which accumulates, as a result of. striking disc-like blanks therefrom is often dilcult to dispose of, and with the scarcity of materials, the wastage is a vital factor.

The' principal object of the present invention is to reduce this wastage to a minimum, by the provision of sheets, cut from strip material, in such manner that a great number of disc-like elements of the same size may be struck therefrom withoutv leaving any so-called recovery pieces and without the necessity of producing secondary products, in an attempt to conserv material.

More specifically, an object of the invention is to provide sheets from which disc-like blanks may be punched or cut, obtaining a greater number of such pieces per ton of sheets than can be obtained by blanking the lpieces from the usual rectangular sheets.

Another object of the invention is to follow such steps in the method of producing the sheets from strip material that they may be made economioally available, and packed for shipment 66 and storage, occupying no greater space than the ordinary rectangular sheets of the same over-al1 dimensions, producing the same number of blanks per sheet, yet weighing less.

A still further object of the invention is to provide sheets each having an area sufficient for a plurality of potential disc-like blank providing spaces with material allowing for threads or webs between the blanks when they are cut or punched l from the sheet, so as to avoid defective products, and whichsheets each have marginal portions allowing for slightly greater threads or webs of material between certain blanks and margins of the sheets. 'I'his allowance for greater marginal threads or webs, among other things, avoids many defective blanks due to careless handling of the sheets, and affords a substantial area not intended for the potential disc-like blanks which may be placed next adjacent to gauge members generally used as machines.

Other objects and advantages of the invention Figure l is a plan view of the old form of rectangular sheet, illustrating by dot andV dash lines the potential disc-like blank producing spaces thereon as quite commonly followedn Figure 2 is a plan View of the new form of sheet illustrating by of the same blanks from a smaller surface.

Figure 3 is a plan View on a reduced scale, showing a typical example of the manner in which strip material may be cut into sheets of the character shown in Figure 2.

In 'the drawing A designates an old form of rectangular sheet of material from which a great number of like blanks of the same size may be struck, but with considerable waste of material. By way of illustration this may be a commercial tin plate used for the production of No. 2 can ends. By dot and dash lines potential can end producing spaces d are indicated, arranged in rows 5 to l0, inclusive, the spaces of any given row being in staggered relation to an adjacent row. This leaves a web or thread of material I I between the openings formed by cutting oi' the can ends and an eiIort is made to make this web or thread as narrow as possible without'producing defective products. The very considerable waste is indicated at the end of each row, as at the so-called recovery pieces or waste areas I2. In the example shown, these areas I2 are each parts of cutting or punching dot and dash lines the production nomical to use them divided diametrically.

I provide a new form of sheet B cut from a strip I6 of parent material, shown in Figure 3.

It is proposed to shear these specially shaped sheets, preferably, altho not necessarily, on a continuous strip mill, so they will be of uniform size sufficiently large to have a plurality of rows of potential can top or disc-like blank producing spaces I6, like in the old form sheet, but without the so-called recovery pieces or waste areas. For instance, in the example shown, the sheet B vhas potential can end producing spaces I6, as

' the opposite margin of 4is of course left between shown by dot and dash lines, arranged in.rows I'I to 22 inclusive, the spaces of any given row being in staggered relation to the spaces of an adjacent row. A web or thread of material I3 the openings formed in the sheet, similar to the web or thread II above mentioned.

The sheet B is preferably provided by severing the parent strip I5 transversely along spaced 1 zigzag or serpentine lines 23. Each line 23 is reversely symmetrical about a transverse axis 2,4 producing spaced tabs 25 and 26 at' opposite margins of the sheet B, as shown in Figures y2 and 3. It' will be noted that the parent strip I5 is divided into a great number of sheetsl B which in cutting position dove-tail together so that there' is no waste of material in the cutting of the parent strip into sheets. The result is that the tabs 25 and 26 at one margin of the sheet are in staggered relation with the' tabs 25 and 26 at the sheet. In other words,

vthe tabs 25 and 26 on one margin of the sheet spaces I6. Each one-half of the space for va potential l "36 parallel thereto each has a base line 32, an

' spaces lvide a tab 26 or arecom'plementary to notches 21 and 26, respectively, on the other margin of the sheet. The zigzag or serpentine cut is so made as to pro- 26 and a notch 26 or 2l, respectively, for each row of potential blankprodulcing tab is also of a size to provide substantially blank.

It is preferred to have each tab 25 oi trapezium shape, so as to have a base line 29, an end edge and diagonally related side edges 3i, in convergingv relation from base line 29 to end edge 30. Obviously each end tab 26 may be likewise formed, but in the example shown end edge 33, a diagonally related side edge 3l and a right angularly related side edge 34. The latter forms a congreet. 'rms adaiapnal material on the tabs. over or above that required for reasonable assurance that the blanks will be full size and that thread or web material will not the punch during the punching operation, advantages not at'once -apparent. Forv instance,

if the edge is nicked due to careless handling,

there is suiiicient material which will notv be needed for production-of the blank to receive the average blow without the nick extending into the blank space I6, whereas the thread or Aweb area Il is in a more protected position. f

In the example shown in Figure 2 there are 6 rows of potential disc-like blank areas thus providing two tabs 26, one on4 each of two diagonal corners oi the sheet, ,and this would be true whenever the number of rows is, even.

, the sheet is dlni'ensioned for an'uneven number lof rows with corresponding tab and -notch for then there would be two tabs 26 on theeach row, same end of the sheet, yet when the sheets are in cutting position, as shown in Figure v3, they dove-tail together` in the same manner, and the same knife or set of knives may be vused to make all cuts of the strip material into sheets.

lllhileA I have herein referred to can endsas typical examples of disc-like blanks which may bevmade from the sheets B, it is understood that this is -merely by way of example, and that the term "disc-like" is used in `a. broad sense to desig- 'nate elements which maybe economically cut in rows in staggered relation, such as polygonal or oval elements. y

The term zigzag is also, used in a broad sense to denne the lines oi severance of the strip ma- .terial into sheets. It is intended to include such terms as serpentine or in-and-out direction, altho it is believed a knife or knives for making tabs of trapezium shape is low in cost oi manufacture and easy to keep sharp.v I

The strip material may,fof course, be of metal, paper, cardboard, plastic board, etc.,`the principal object of the invention being. to conserve material, worthV saving, but which in the past has been wasted, cost whenrplentiful, or to the tendency of producers to continue use of oldequipment regardless ofthe need for conservation.

I claim: y

1.l The method oi'providingsheets of the same over-all dimensions, from long, thin strip material, Vfor the'economical production oi a great number of like blanks therefrom, which consists in severing said strip material transversely along zigzag lines at uniform, widelvspaced intervals to produce sheets having spaced tabs at opposite ftinuation oi opposite parallel sides 35 of the four sided sheet B which sides 35 parallel theaxes of the rows I'I-22 of spaces I6.

In practice, I find it desirable altho not essential to provide the tabs 25 and 26, each with an altitude 36 sufficiently great as to provide a thread 31 or material between the blank producing space I6, partially provided by the tab, and the end edge of the tab, that is ygreater than the narrowest portion of the web or thread I3 between adjacent I6, when the blanks are punched from the sheet. This .may beaccomplished by allowing a. minimum area of material for a thread 38 at each base 39 ofthe notch at the opposite side of the edges, each tab of asize to provide substantially' one-half of a potential blank.

2. The method of producing sheets 'of the same over-all dimensions, from long, thin strip material, each `having an areal suiilcient for a great number of parallel rows of potential disc-like blank producing spaces, with the spaces of any given row in staggered relation to an adjacent I. row, which consists vin severing said strip material transversely along zigzag lines at uniform, widely spaced intervals to produce sheets, each having a plurality of spaced 'tabs at opposite edges, each tab of a sizeto provide substantially one-half the area of one of said potential disclike blank producing spaces, and axially aligned with one of said rows. ll

3. The method of providing sheets of the same over-all dimensions, from lo'ng. thin strip material, each having an area sumcient for a great be drawn into the die by has.

However, if

due mainly either to/ its initial 'low number of parallel rows of potential disc-like blank producing spaces, with the spaces of any given row in staggered relation to an adjacent row, which consists in severing said strip material transversely along like zigzag lines at uniform, Widely spaced intervals to produce sheets, each having a plurality of spaced tabs at opposite edges, each tab complementary to the space at the opposite edge of the sheet between the tabs thereof, and each tab of a size to provide substantially one-half the area of one of said potential disc-like blank producing spaces, and axially aligned with one of said rows.

4. As an article of manufacture, a four sided sheet for the enonomical production of a great number of disc-like blanks of a given size therefrom, said sheet having two opposite tabbed side margins, the tabs each being of a size to provide substantially one-half the area of the given blank, and two opposite, straight, parallel side margins Aat least coextensive with the body of the sheet.

5. As an article of manufacture, a four sided sheet dimensioned to provide a great number of parallel rows of potential disc-like,v blank producing spaces, with a like number of said potential disc-like blank producing spaces in each of the rows, and the spaces of any given row in staggered relation to an adjacent row and with sufficient material to provide threads of material between the blanks when cut from the sheet, said sheet having two opposite straight sides paralleling said rows of spaces and the other two sides having spaced tabs aligned with the axes of said rows, said tabs each of a size to provide substantially one-half of the area of one of thepotential blank producing spaces at the end oi its respective row.

6. As an article of'manufacture, a four sided sheet dimensioned to provide a great number of parallel rows of potential disc-like blank producing spaces, with a like number of said potential disc-like blank producing spaces in each of the rows, and the spaces of any given row in staggered relation to an adjacent row and with suflicient material to provide threads of material between the blanks when cut from the sheet, said sheet having two opposite straight sides paralleling said rows of spaces and the other two sides having spaced tabs aligned with the axes of said rows, said tabs each of a size to provide substantially one-half of the area of one of the potential blank producing spaces at the end of its respective row, and the tabs at one side of the sheet being in staggered relation to the tabs at the opposite side of the sheet.

' '7. As an article of manufacture, a four sided sheet dimensioned to provide a great number of parallel rows of potential disc-like blank producing spaces, with a, like number of saidpotential disc-like blank producing spaces in each of the rows, and the spaces of any given row in staggered relation to an adjacent row and with sufcient material to provide threads of material between the blanks when cut from the sheet, said sheet having two opposite straight sides paralleling said rows of spaces and the other two sides having spaced tabs aligned with the axes of said rows, said tabs each of a size to provide substantially one-half of the area of one of the potential blank producing spaces at the end of its respective row, each tab being of trapezium shape and having an altitude sufliciently great to provide a thread of material between the blanks cut partially therefrom and the edge of the tab opposite its base line, greater than the thread of material between the other blanks of the row.

8. The method of providing elongated sheets from long, thin strip material of substantially uniform width, for the production of a great number of like blanks therefrom, which consists in severing said strip transversely, at spaced intervals greater than the width of said strip, along zig-zag lines reversely symmetrical about an axis normal to the edges of the strip, to produce elongated sheets, each having spaced tabs at opposite transverse edges, and substantially parallel longitudinal edges.

9. As an article of manufacture, a sheet shaped and dimensioned to economically provide a great number of parallel rows of spaced potential disclike blank producing spaces, with a like number of said spaces in each row and the spaces of any given row in staggered relation to the spaces of an adjacent row, whereby the terminal blank producing spaces of any given row are oiset with respect to the terminal blank producing spaces of any next adjacent row, and at least the opposite margins of said sheet adjacent said terminal blank 'producing spaces being of zigzag shape, following the said terminal spaces so closely at the axes of the rows that upon cutting the blanks from the sheet, only ne threads of waste material are produced between the terminal blanks of the rows and said zigzag margins at the axes of said rows.

10. As an article of manufacture, a sheet shaped and dimensioned to economically provide a great number of parallel rows of spaced potential disc-like blank producing spaces, with a like number of said spaces in each row and the spaces of any given row in staggered relation to the spaces of an adjacent row, whereby the terminal blank producing spaces of any given row are offset with respect to the terminal blank producing spaces of any next adjac ent row, and at least the edgest of the sheet at the ends of the rows being deiined by a series of intersecting lines, the corresponding lines at the opposite ends of each row being parallel and disposed in close proximity to the terminal spaces of such I'OW.

ROBERT W. MESSENGER. 

